Difference between revisions of "TF EIMLab8 Writeup"
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(Created page with 'Lab 8 The Diode Objective: Measure the current-voltage curve of a silicon diode. =Reverse current= 1.) Construct the circuit below using a DC power supply, a diode. [[File:Lab…') |
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3.) Measure the diode reverse current <math>I_r < 1 \mu A</math> as a function of the DC supply voltage. (30 pnts) | 3.) Measure the diode reverse current <math>I_r < 1 \mu A</math> as a function of the DC supply voltage. (30 pnts) | ||
| + | |||
| + | IN5230-B-T (4.7 Volt Zener Diode) | ||
| + | |||
| + | {| border="3" cellpadding="20" cellspacing="0" | ||
| + | | Bias Volts || V_{scope} (1 M\Omega)(mV)|| Keithley ammeter | ||
| + | |- | ||
| + | | 0.6 \pm 0.001 || 2 \pm 1 || 1.24 \pm 0.01 | ||
| + | |- | ||
| + | |0.9 \pm 0.001||10 \pm 1|| 8.69 \pm 0.01 nA | ||
| + | |- | ||
| + | | 1.05 \pm 0.005||22 \pm 0.5 mV ||24.3 \pm 0.05 nA | ||
| + | |- | ||
| + | |1.16 \pm 0.005 ||40 \pm 1 mV ||49.4 \pm 0.05 nA | ||
| + | |- | ||
| + | | 1.23 \pm 0.005 || 56 \pm 1 mV||78.6 \pm 0.05 nA | ||
| + | |- | ||
| + | |1.27\pm 0.005 ||68 \pm 1 mV ||98.2 \pm 0.005 nA | ||
| + | |- | ||
| + | | 1.20\pm 0.005 || 75 \pm 1|| 118.2 \pm 0.5 | ||
| + | |- | ||
| + | | 1.35 \pm 0.005 || 93 \pm 1||158.2 \pm 0.5 | ||
| + | |- | ||
| + | | 1.4 \pm 0.005||112 \pm 1 ||213.0 \pm 0.1 | ||
| + | |- | ||
| + | | 1.45 \pm 0.005 ||132 \pm 1 ||279.1 \pm 0.1 nA | ||
| + | |- | ||
| + | | 1.50 \pm 0.005 || 155 \pm 1||366 \pm 0.5 nA | ||
| + | |- | ||
| + | | 1.55 \pm 0.005 ||182 \pm 1 ||474 \pm 0.5 | ||
| + | |- | ||
| + | |} | ||
4.) Fill in the blank. The reverse biased diode act as a constant _______________ source. (5 pnts) | 4.) Fill in the blank. The reverse biased diode act as a constant _______________ source. (5 pnts) | ||
Revision as of 01:43, 15 February 2011
Lab 8 The Diode Objective: Measure the current-voltage curve of a silicon diode.
Reverse current
1.) Construct the circuit below using a DC power supply, a diode.
2.) attach an Oscilloscope set to 1M input impedence so the probe is located at point B. The oscilloscope's internal resistance will serve as a Resistor (R) to measure the voltage across the diode and calculate the current.
3.) Measure the diode reverse current as a function of the DC supply voltage. (30 pnts)
IN5230-B-T (4.7 Volt Zener Diode)
| Bias Volts | V_{scope} (1 M\Omega)(mV) | Keithley ammeter |
| 0.6 \pm 0.001 | 2 \pm 1 | 1.24 \pm 0.01 |
| 0.9 \pm 0.001 | 10 \pm 1 | 8.69 \pm 0.01 nA |
| 1.05 \pm 0.005 | 22 \pm 0.5 mV | 24.3 \pm 0.05 nA |
| 1.16 \pm 0.005 | 40 \pm 1 mV | 49.4 \pm 0.05 nA |
| 1.23 \pm 0.005 | 56 \pm 1 mV | 78.6 \pm 0.05 nA |
| 1.27\pm 0.005 | 68 \pm 1 mV | 98.2 \pm 0.005 nA |
| 1.20\pm 0.005 | 75 \pm 1 | 118.2 \pm 0.5 |
| 1.35 \pm 0.005 | 93 \pm 1 | 158.2 \pm 0.5 |
| 1.4 \pm 0.005 | 112 \pm 1 | 213.0 \pm 0.1 |
| 1.45 \pm 0.005 | 132 \pm 1 | 279.1 \pm 0.1 nA |
| 1.50 \pm 0.005 | 155 \pm 1 | 366 \pm 0.5 nA |
| 1.55 \pm 0.005 | 182 \pm 1 | 474 \pm 0.5 |
4.) Fill in the blank. The reverse biased diode act as a constant _______________ source. (5 pnts)
Forward Current
- now swap the diode direction and repeat the measurement in the previous section.
Graph
- make the same measurements in parts 1 and 2 above for a germanium diode.
- Plot the diode current (on the ordinate) versus the diode voltage (on the abscissa)for both diodes on the same graph. (50 pnts)
Questions
- The reverse biased diode acts like a constant ____________. (10 pnts)
- The forward biased diode has a very __________ resistance. A reverse biased diode has a very ____________ resistance.(10 pnts)
- The approximate DC forward resistance for diode #___________ is _________ when the forward current is _______________.(10 pnts)
- The approximate DC reverse resistance for diode #___________ is _________ when the forward current is _______________.(10 pnts)
- The silicon diode #___________ has an approximate turn on voltage of ___________.(10 pnts)